What can cause a change in a ship's draft?

A ship's draft is defined as the vertical distance between the waterline and the bottom of the hull (the keel). This measurement is crucial for assessing how deep the ship is sitting in the water and can be influenced by several factors.

The primary factor causing a change in a ship's draft is the loading of fuel and stores. When fuel and supplies are loaded onto the ship, it adds weight, which consequently increases the ship's displacement and causes it to sit deeper in the water. This increase in weight leads to a deeper draft. Conversely, if fuel or stores are consumed, the ship will become lighter, leading to a decrease in draft as the vessel rises higher in the water.

Other factors such as weather conditions, water temperature, and alterations in ship speed can affect buoyancy and stability but do not have a direct impact on the load-bearing capacity and physical condition that alters the draft as clearly as the loading or unloading of weight. Understanding how loading and unloading affects draft is essential for navigation and ensuring safe passage, particularly in shallow waters or when docking in ports with depth restrictions.